WoodGas Technology

WoodGas products use an electric fan to control the airflow into a combustion chamber. This has three effects.

First, due to the way the air is directed through the fuel, smoke production is nearly eliminated.

Second, because the smoke is nearly consumed in the combustion process, the heat produced from a given amount of wood is greatly increased.

Last, the heat output and fuel consumption can be controlled to some extent. This allows the heat output to be varied for different applications, such as cooking.

Products

Spenton LLC currently sells three products based on WoodGas technology.

CampStove LE

The WoodGas CampStove LE is designed as a small camping stove suitable for backpacking and bicycle camping. It produces 10,000 btu/hr of heat on its high setting. It weighs 23 oz and will burn about 10 minutes on one load of twigs. Two AA batteries power the stove, giving 10 hours of burn time.

CampStove XL

The WoodGas CampStove XL is designed as a larger camping stove suitable for car or motorcycle camping or canoeing. It produces 12,000 btu/hr of heat on its high setting. It weighs 34 oz and will burn about 20 minutes on a load of twigs. Two AA batteries power the stove, giving 9 hours of burn time.

Fireplace

The WoodGas Fireplace is designed as an outdoor patio fireplace, or as a large outdoor heating device. It may be used as a heater for distilling maple syrup, or as a heating device for a large cooking pit. It produces 50,000 btu/hr of heat for about 35 minutes on one load of twigs. The Fireplace is powered by a (supplied) 9V adapter which will work in any AC outlet (120 or 240V AC).

Solar Charger

The spenton solar charger is a commercially available solar charger which has been modified to work with the camp stove products (LE and XL). It has a battery compartment which holds two AA batteries. The charger plugs directly into the stove and draws needed power from both the solar panels and from the batteries. When the charger is unplugged from the camp stove, the solar charger recharges the batteries in the battery compartment.

Fuels

In general, any wood based fuel will work in any WoodGas product. The fuel needs to be small enough to fit in the product and allow air flow through the stack of fuel. Naturally occuring fuels include small twigs, crushed pine cones, or wood chips.

Compressed sawdust pellets work in WoodGas products just as chips or twigs. They produce the same heat output as chips or twigs. But since they are densified in the manufacturing process, they burn for much longer than natural wood fuels. Typically, compressed wood pellets will burn for 3 times longer than natural fuels. And since they are dried and of a uniform shape, will produce a more even and consistent flame.

The combustion methods used to combust the fuel utilize the hydrogen which is present in wood. Charcoal is essentially wood in which the hydrogen has been burned off. For this reason, charcoal does not burn well in woodgas products. Though some is produced as a byproduct of fireplace operation.

Starting/Burning

WoodGas products are started differently than other fires. Combustion is started at the top of fuel stack with some sort of fuel starter - dry tinder or commercial fire starters.

Once started, the fire then burns down toward the bottom of the combustion chamber. As combustion progresses, a layer of charcoal is formed on the top of the fuel which then falls with the flame front as the fuel is consumed. When combustion is complete, the charcoal layer remains on the bottom of the combustion chamber. The charcoal can either be consumed by driving the fan longer, or in the case of the fireplace, the air flow can be shut off, and the lid placed on the fireplace to let the charcoal cool. In the case of the fireplace, the charcoal can be used as charcoal in any charcoal burning system.